Extraction and mixed-pressure turbine



J. H. DURAN. EXTHACTION AND MIXED PRESSURE TURBNE.APmlcAuoNFILEDJUNE14,191S.

lrwvearwtor: JOHN FLDcfraw,

His ofttorneg.

' chests.

"UNITED STATES PATENT OFFICE.

JOHN H. DORAN, OF SOHENEOTADY, NEW YORK, `AssIcTNOR 'ro GENERAL ELECTRIC`COMPANY, A CORPORATION or NEWKYORK.

EXTRAOTION n AND MIXEDLPRESSURE TURLBINE.

To all whom it may concern: v

lBe it known that I, JOHN H. DORAN, a citizen of the United States,residing .at Schenectady, in the county of Schenectady, State of NewYork, have invented certain new and useful Improvements lin .Extractionand Mixed-Pressure Turbines, of which the following is a specification.

The present 'invention relates generally to elastic fluid turbines ofthe type having,

a radial llow blade system comprising two bladesv carrying elements orrotors 'arranged to rotate vin opposite directions, each ele mentdelivering power to a'shaft which, for example, may be connected totherotor of an electric generator or other power consuming agent,

' The object .of my invention is to provide an improved arrangement ofpartswhereby steam atan intermediate pressure can -be extracted fromthe' blade system 'after it has performed workl lin the turbine orwhereby .intermediate or low pressure steam can be admitted totheturbine to perform work therein in the lowpressure stages or portion. d

For -a consideration of what I believe to be novel and my. invention,attention is -directed to' the accompanying description and claimsvappended thereto.

I n the drawing, Figure 1 isa partial sec- -tional view. of a. turbinehaving oppositely,

rotatin bla'de systems; Fig. 2"is a detail vie'wo a part ofthe steamchest taken on line 2--2of Fig. 1; Fig. 3 is a. detail view of a portionof the auxiliary steam chest, and Fig. LLis a sectional view of thesteam 5 indicates the innerportion of one' of the rotors whichis'mounted on a stubv shaft, A6, the latter in turn being connected toone of the main shafts (not shown).l To the said inner-portion is'connected an interme;

diate rotor portion 7, by an expansion ring 8.A 9 indicates the outerrotor portion which is connected to the intermediate portion by theexpansion ring'10. The right hand side of the machine is 'a duplicate ofthe left and for that reason can be readily understood .without furtherillustration.

,.,To the inner, intermediateand outer portions `of the rotor areconnected concentric rir'lgsy or blades 11, each of Awhich is securedSpecification of Letters Patent. Patented Alig'. 17,1920. Applicationmea June 14,

isi-s. serial No. 239,942.

to the rotor by an expansion ring 12 which is similar to but of smallersize than the eX pansion rings which conne'ctithe parts of the rotor. Aswill be seen these expansion rings are provided with enlarged roundedrings carried thereby. The purpose of theseeXpansion rings is to dividethe partsinto regions or Zones of different temperatures,

the transfer of heat through saldrings being relatively slow andrestricted.r Further more, these rings permit the-parts to ex# pand andcontract at different rates without causing the stresses in one partbeing transmitted to the other parts. They also serve as means toprevent the escape of steam between dilerent parts .as will be evidentupon inspection.

Located between the 44.blade ringsA 11., are other and concentric bladeyrings 14: whichy are supported in the same manner bythe right handrotor portions. The `outer portion i; ofthe rotor is also'provided 'withradially extending blades or buckets '15: through which low pressuresteam flows in anaxial direction. 16 indicates stationary vnozzles orfluid discharging deyices which receive steam from the radial flow bladesystem ol3 the machine, c'. e.,-the rings of blades 1l and '14, anddeliver it to the axialtlow portion,

only one of which is illustratedl Thenozl zles are supported by rings 17and 18 which in turn are supported by an annular member 19 and diagonalbraces 20. The member is supported by an annular rib 21 on the inside ofthe inclosing casing22 and also by one or more pins 23 which hold-itagainst` i 24 and 25, of which the disk 24, rotates while the disk 25-is stationary. Tov reduce the leakage between .th'evpdisks'the opposedfaces thereof are provided with:fa-labyrinthpacking 26 of any suitable`constructiomdn this casealt'ernate projectionsb andfjgrooves.

Through this packing'Y live steam flows f radi,v

ally rom the center toward'. the outside and as the pressure thereinfrom point to point. ,substantially corresponds to that' ofthe theinside of the casing of the turbine in any suitable manner. Between "theplate and chest is an expansion ring 32 acting as the lvother expansionringsdo to compensate for unequal stresses due to .temperature changes.The thrust' and balancing disk A25 is carried by the stationary steamchest,

said parts being unitedby two concen-v trica'lly arranged expansion.rings 33 which rings in addition to forming a supporting means alsoforni steam tight joints to prevent leakage' of steamfrom the chest.

vSteam from theunainI supplyv chamber 28 flows to the inner blades nearvthe axis of the machine in the manner-indicated by the arrows 34.' Steamfrom the overload chamber 30 flows through a 'series ot' uniformlyspaced'axia'lly extending holes or passages. 35,36, and 37 in the thrustand balancing disks and inner "portion 5 vCif-the rotor to anintermediate pressure region of the blade system.

Referring n ow to the arrangement of parts whereby steam may beextractedfrom the turbine for heating purposes, r whereby low pressure rsteam maybe admitted to perform work inthe turbine, 40 'indicates an auxiliarysteam chest lwhich may be supported in any suitable manner, preferablyby the/main chest. -It may be made integraltherewith or it maybe boltedthereto, as shown in the drawing. The arrangement will be determinedprincipally by. the construction of the main steam chest. If the latter'is a forging the auxiliary chest will beA made separate; if a casting,the vtwo chests maybe made in one piece. yMounted or formed on the mainchest is apshoulder 4'1 to which the auxiliary c hest is secured bybolts 42, and in said shoulder are holes or passages V43 registeringwith similar holes or passages in the auxiliary chest and through whichsteam may enter or leave the turbine. 'To' the shoulder 41 is `attachedby an expansion ring 44 an annulus 45 forming part of an axial packing.rounding this .annulus and forming the other part of the packing is asecond annulus 46 which is secured to theintermediate part of the rotor,by Aan expansion ring 47. The opposed faces of the two parts areprovided with 'alternate grooves Surand projections or yothermeans-.tored'uce .and from the space between the thrust and balancingdisks 24 and 25.* Steam'vfrom an intermediatepressure region in therotor flows laterally through the axial holes or passages 49 in theyintermediate portion 7 ot the rotor as indicated by the small 'arrows.The passages 49 which open laterally from the main steam path should benumerous so as to equalize the flow ofsteam from the region' otintermediate pressure' between the parts of the blade-system, Thepassages are shown 'extending .axially since this is the simplestconstruction but they may be formed otherwise il desired. 'lf flowpressure steam is supplied from an external source the iiow of steamis'of course in th'e opposite direction but through the same passages Inorder to convey steam from or to the turbine the auxiliary steam chestis provided with an extension lon its upper side in'vvhichvis seated thepipe' 50, the latter extendingthrough the wall of the turbine casing inany appropriate manner. As shown, two auxiliary steam chests areprovided for each side of the machine, there being in all four pipes 50,of which two are shown.

Then operating as an extraction machine under normal' load conditions,vsteam will issue from the numerous passages 49 at about 15 lbs. gage,pressure, for example,

.into the annular equalizing chamber 5l from -which it flows over theperiphery 'of thethrust and balancing disks into the annular chamber 52and thence through Athe passages 43 into the auxiliary chests'40 andoutlet 'pipes 50. The pressure ofthe steam leaving the packing spacebetween the disks would under the conditions described also be about 15lbs. gage, and steam from both in all-cases, howevergsteam admitted toor.

yis not limited tri-having oppositely r or admitting it to both sides ofthe rotor in the same region, the axial balance of the rotor is notdisturbed, a feature of the utmost importance in a turbine of this typewhere the parts of tlieblade system revolve ances are small. l

As previously stated there are two packings, one a radial. iow packingand the other an axialjflow packing, lThis arrangement is madenecessarybythe `fact thatsufiicient balancing pressure cannot be had ifthe steam isA allowed to expand to the eX- haust pressure of the turbineat the outside diameter of the balancing .'disks. Siiliicient balancingpressure could bev obtained if the diameter ef -the radial packing couldbe made greater but this is impossible because they bore of thesurrounding wheel cannot be enlarged on account of the high stresses inits hub. The provision of the axialflow packing, however, inseries withthe radial flow packing permits of the necessarv iiicrease of` pressureat the outside diameter .of the balancing disksand radial pfiickiiig. ,Itake advantage of the fact that two packings are required by providing asteam passage between them, and by utilizingthis passagealong withpassages49 in the roto'r and also chambers 5l and 52 and auxiliarysteam. chests 40 it 'is apparent that'steam can be ei'itracted from oradmitted to the turbine 'without essentially modifying the structure ofthe turbine itself.

'I'n the broader aspects of my invention it blades since one set of!bladesv can while .the others are held stationary. ever, the' double-roion system ableL because of s superior e iency. Neither is limited inits broader aspects to having an axial flow packing in series with theradial flow pack: forun some instances it is possibleto provide tworadial' flow packings and. obtain the desired result,

flowing from' the auxiliary chest will flow through the space betweentheV two packings.

'In accordance' with thefprovisionsof the patent statutes, I havedescribed the principle of operation of my invention,'together with theapparatus which I now consider to representthe best embodiment thereof;but I desire to have'it understood that the apparatus shown is onlyillustrative and that the invention'can becarried outbygother means.

What I claim as new and`desire to secure by Letters Patent of the UnitedStates, is 1.' Inan elastic fluidturbine, the combination of relativelyrotating parts, two separate sets vof packings for reducing leakage,

ysaid sets ofpackings being spaced to form an annular passage betweenthem, fluid conveying means Which connects a region of 1ntermediatepressure 1n said rotating parts rotatingvpart andthe turbinecasing,fluid passages in one of said parts, .a chamber adapted top receivefluid vfrom or admit it to saidpassages, a chest having a chamber incommunication 4with the' first mentioned 'chambei-,and a conduit openinginto the chest and also to the outside of the casing.

8. In an elastic Yfluid turbine, the combination of rotors having bladeswhich rotate in opposite 'direci';ions,` said rotors having passagesopening inte region of intermediate pressure, sets of pacllzings onopposite sides of the rotating structure. the parkings on each sidebeing separated by a steam passage which is in communication withcertain of the iii'st named passages, steam chests on oppositesides ofsaid rotors which communicate with said steam passages, and conduits forconveying steam between the chests and the outside of the 'turbinecasing.

el. In an elastic fluid turlfne, the coinlfination oi a rotor having a iil liow blade system and also passages which open into a region ofintermediate pressure in the blade system, apair of thrust and balancingdisks,

-a labyrinth packing between the disks, a

second packing through which exhaust from the labyrinth packing flows,the two packings being separated by'a passage through y which steamflows to orfroin said passages in the rotor, a steam chest whichcommunicates with and a coinA conveying steam to or nu the chest.

5. In an elastic fluid t "bine, the combination of arotor which has aradial flow blade system, a pair of thrust and balancing disks, one ofwhich is connected to the rotor, a labyrinth packing between the disks,passages in the rotor through which steam may flow into or from therotor and over the periphery olf'the disks, a second packing whichmaintains a pressure at the end of the labyrinth packing above thepurbine exhaust pressure,- a main steam chest' supported by the casingwhich carries one of the thi disks, an auxiliary chest which communcates with the region between the two packiiigs, and a conduit throughwhich steam flows into or from the auxiliary chest. i

6. In an elastic fluid turbine, the combination of a rotor having aradial-'flow blade annular body of the packing, and a conduitcommunicating with the chamber in the chest.

7. In an elastic Huid turbine, the combination of a rotor having aradialliow blade system and also lateral. passages, a pair of thrust andbalancing disks, one ofv Which is connected to ltherotor, a packingbetween the disks tol reduce leakage, a steam chest which is supportedbythe turbine casing, supplies steam to .the blade system 4andalso-supports one of the disks, va second packing which receives steamfrom the first and comprises two concentric annular bodies, one of Whichis supported by the rotor, and the' other by the steam chest, anauxiliary chest which is in communication .with the lateral passages inthe rotor and the'space between the packings, and -a conduit openinginto the auxiliary chest. v

8. In an elastic-duid turbine, the combination of a rotor having radialand axial-How blade systems, a ,pair of thrust and balancing disks, oneofwhich'is carried by the rotor, a packing between the disks, astationary annnlar .steam chest located between a Wall of the turbinecasing and the rotor Whichsupports one of the disks, a second packingwhich receives exhausty from the 4first and comprises two concentricannular bodies, said bodies being located Within that portion of' therotor Which carries an axial flow blade system, means for attaching oneof the bodies to that portion of the roto'r which carries a radialfiow'blade system, and means-for at- 'Lamers taching the other .body vtothe stationary steam chest. l

9. In an elasticuid turbine, the combination of rotors having oppositelyrotating blades, a pair of thrust and balancingdisks for each.v set ofblades, one of Which iscarried bya rotor, a stationary steam chest whichlateralspassages, one set supplying steam'for overload purposes,thesecond'setbein'g arranged to .discharge steam for extractionlpurposes and toV receive steam for mixed pressure operation, thrust and4balai'icing disks, leakage reducing packing means between the edges ofthe disks and the nal exhaust, means foriadmitting steam to the firstset of lateral passages, and'means for conveying steamover the edges ofthe disks to or Jfrom the second set of lateral passages.

In witness whereof, I have hereunto set my 4hand this 12th day ofJune,vl9l8.

JOHN n. Dorian.

